* Rename all member variables and methods that reference the cross hair
code in draw panel object from cursor to cross hair to eliminate confusion
between the two concepts.
* Rename cursor capture call backs in draw panel object to improve code
readability.
* Create helper class for turning off the cross hair while drawing.
* Remove redundant block clear code.
* Remove redundant mouse capture call back reset code when end capture
call back is called.
* Remove unused function definitions in base draw frame object.
* Lots of minor coding policy and doxygen comment fixes.
* Fix rendering bug in GerbView caused by wxDC scaling change caused by
setting the wxDC clipping region.
* Eliminate the need to have optional background erasing as the change
above fixed that problem as well.
* Default cursor handling improvements.
* Encapsulate file name member of base screen object.
* Encapsulate associated screen member of schematic sheet object.
* Create add screen method to schematic sheet object to simplify setting
the associated screen.
* Move the change file name code in the schematic sheet object to the edit
sheet method in the schematic editor frame object to eliminate message
dialogs.
* Improve reference counting in schematic screen object.
* Add helper type definitions for changing schematic object storage to C++
containers.
* Fix a minor problem with wxFileDialog to open a file that no longer
exists in PCBNew.
* Make GerbView open file behavior the same as PCBNew.
* Remove redundant PCB file wild card definition.
* Add open file refactor task to the todo list.
* Fix some minor code formatting issues.
* PCBNew remembers last net list read during the current editing session
as well as between project editing sessions. Closes bug 576902.
* Separate PCBNew application settings from project file settings and
allocate them dynamically instead of statically to make it easier to
eliminate global variables.
* Split out application specific command IDs to prevent unnecessary rebuilding.
* Eliminate duplicate menu and tool bar command IDs.
* Split component library editor and viewer definitions to separate header files.
* More component library and document file merge code.
* A bunch of minor string readability and consistency fixes.